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green wintergreen, green-flower shinleaf, green-flower wintergreen, greenish wintergreen, pyrole à fleurs verdâtres

American shinleaf, American wintergreen, pyrole d'amérique, round-leaf pyrola

Habit Plants rhizomatous, (0.7–)1.4–2.2(–2.7) dm. Plants rhizomatous, 0.1–0.3(–0.4) dm.
Leaves

sometimes reduced or absent;

petiole 8–60 mm, channeled adaxially, glabrous;

blade not or, rarely, obscurely maculate, dull and light green to purplish abaxially, shiny and dark green, rarely with white tissue bordering larger veins adaxially, ovate, elliptic, obovate, or round, (6–)18–28(–33) × (5–)10–30 mm, coriaceous, base rounded to truncate or decurrent, margins entire or crenulate to crenulate-serrulate, apex obtuse to rounded.

petiole (8–)15–70 mm, channeled adaxially, glabrous;

blade not or, sometimes, maculate, dull to shiny and light green to green abaxially, shiny and dark green sometimes with white tissue bordering larger veins adaxially, ovate to obovate or round, 16–73(–80) × 16–70 mm, coriaceous, base rounded to decurrent, margins crenate, apex subacute to obtuse, rounded, or retuse.

Inflorescences

1–2(–3) per stem, (1–)2–8(–17)-flowered;

peduncular bracts absent or 1(–2), subulate to linear-lanceolate, 2.8–5 × 0.5–0.8 mm, membranous, margins entire or erose-denticulate;

inflorescence bracts subulate to lanceolate, usually shorter than, rarely longer than, subtended pedicels, (2.3–)3–5(–7.7) × 0.5–0.8 mm, membranous.

1 per stem, 4–22-flowered;

peduncular bracts 1–5, oblong-ovate, 5.5–13 × 2–4 mm, chartaceous or membranous, margins entire;

inflorescence bracts lanceolate-ovate, longer than subtended pedicels, 4–12 × 1.2–3 mm, chartaceous.

Pedicels

3–8 mm.

4–8 mm.

Flowers

calyx lobes appressed or spreading in fruit, green or pinkish with margins hyaline to white, deltate to deltate-ovate, (0.9–)1.2–1.7 × (0.9–)1.3–1.9 mm, margins entire or obscurely erose-denticulate, apices acute to obtuse;

petals greenish white to yellowish white, obovate, (4–)4.5–9 × 3.3–5.5 mm, margins entire or obscurely erose-denticulate;

stamens 4–7.5 mm;

filament base 0.7–1.2 mm wide;

anthers (2.1–)2.5–3(–3.7) mm, apiculations absent or less than 0.1 mm, thecae creamy white or tan to yellowish, tubules yellowish brown, 0.7–1.1 mm, abruptly narrowed from thecae, lateral walls not touching or connivent distally, pores 0.2–0.4 × 0.1–0.2 mm;

ovary smooth;

style exserted, (4–)5–7 mm;

stigma 0.9–1.5 mm wide, lobes erect.

calyx lobes appressed or spreading in fruit, green or pinkish with margins hyaline to white or pinkish, ovate, ovate-oblong, or obovate, 2–4.3(–4.5) × 1.4–2 mm, margins entire or erose-denticulate, apices obtuse to acute;

petals white, often suffused with pink, obovate to round, 6–10.5 × 4.5–5 mm, margins entire;

stamens 4–7 mm;

filament base 0.6–0.9 mm wide;

anthers 2–4.1 mm, apiculations 0.1–0.3 mm, thecae creamy white or greenish white to pink or reddish, tubules yellowish brown to pink or reddish, 0.2–0.3 mm, gradually or abruptly narrowed from thecae, lateral walls touching for most of their lengths, pores 0.1–0.2 × 0.1–0.2 mm;

ovary smooth;

style exserted, 6–9 mm;

stigma 0.7–1.6 mm wide, lobes erect.

Capsules

depressed-globose, 3–4.5 × 3.5–6.4 mm.

depressed-globose, 3–3.5 × 4.2–5 mm.

2n

= 46.

= 46.

Pyrola chlorantha

Pyrola americana

Phenology Flowering Jun–Aug. Flowering Apr–Jun.
Habitat Moist to dry, coniferous and deciduous forests Moist to dry, deciduous or coniferous forests, bogs
Elevation 10-3700 m (0-12100 ft) 10-2100 m (0-6900 ft)
Distribution
from FNA
AK; AZ; CA; CO; CT; DE; ID; MA; MD; ME; MI; MN; MT; NE; NH; NJ; NM; NV; NY; OH; OR; PA; RI; SD; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; SK; YT; SPM; Europe
[WildflowerSearch map]
[BONAP county map]
from FNA
CT; DE; IL; IN; KY; MA; MD; ME; MI; MN; NC; ND; NH; NJ; NY; OH; PA; RI; SD; TN; VA; VT; WI; WV; MB; NB; NF; NS; ON; PE; QC; SPM
[WildflowerSearch map]
[BONAP county map]
Discussion

E. Haber (1993) interpreted some herbarium specimens with intermediate morphologies and abnormal pollen as putative hybrids between Pyrola chlorantha and P. minor, and between P. chlorantha and P. picta. Leafless forms of P. chlorantha can be distinguished reliably from those of P. picta by the size and shape of the calyx lobes.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

The relationship between Pyrola americana and other members of sect. Pyrola awaits resolution; various interpretations exist. Some authors follow M. L. Fernald (1920) in treating it as conspecific with the Eurasian P. rotundifolia. B. Křísa (1966, 1971) considered P. americana to be morphologically distinct from P. rotundifolia, treating it as P. asarifolia subsp. americana (Sweet) Křísa. E. Haber (1972) likewise treated P. americana as a subspecies of P. asarifolia, noting similarities in stamen morphology, flavonoid chemistry, and geography. Later, in a detailed study of P. asarifolia, Haber (1983) did not address directly the position of P. americana, which he did not include as either an infraspecific taxon or synonym of P. asarifolia. The taxon is maintained here as a distinct species pending further studies.

M. L. Fernald (1920) referred plants from Newfoundland and the Gulf of St. Lawrence area, which grow on barrens and in spruce forests, often on calcareous substrates, to Pyrola rotundifolia, considering them indistinguishable from European plants. E. Haber (1972) interpreted them as ecotypic variants of P. asarifolia subsp. asarifolia, noting the occurrence of similar populations outside that area.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 8, p. 381. FNA vol. 8, p. 380.
Parent taxa Ericaceae > subfam. Monotropoideae > Pyrola Ericaceae > subfam. Monotropoideae > Pyrola
Sibling taxa
P. americana, P. asarifolia, P. elliptica, P. grandiflora, P. minor, P. picta
P. asarifolia, P. chlorantha, P. elliptica, P. grandiflora, P. minor, P. picta
Synonyms P. oxypetala, P. virens, P. virens var. convoluta P. rotundifolia var. americana
Name authority Swartz: Kongl. Svenska Vetensk. Akad. Nya Handl. 31: 190, plate 5. 1810 , Sweet: Hort. Brit. ed. 2, 341. 1830 ,
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